Gao Li, Zheng Youxiong, Tang Yan, Yu Jianwei, Yu Xingchang, Liu Bingxin
Qinghai Provincial Key Laboratory of New Light Alloys, Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming, Qinghai University, Xining, 810016, PR China.
Heliyon. 2020 Apr 28;6(4):e03853. doi: 10.1016/j.heliyon.2020.e03853. eCollection 2020 Apr.
The phosphoric acid-based metakaolin geopolymers were prepared by regulating HPO/AlO ratios. X-ray diffraction (XRD), thermogravimetry and differential scanning calorimeter (TG-DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to determine the reaction process and phase formation. The results showed that the metakaolin calcined from Kaolinite mainly consisted of quartz crystalline phase and amorphous phase. The diffraction peak for quartz obviously became lower with the increasing of HPO/AlO ratios. The excessive quartz from metakaolin did not totally take part in the chemical reaction. The polymeric structure of -P-O-Si-O-Al-O constitutes the main building block of phosphoric acid-based metakaolin geopolymeric structure. The optimized compressive strength was 29 ± 2 MPa with HPO/AlO molar ratio = 1.3:1. The simulation of the total deformation under 29 MPa load and the total heat flux at 1400 °C of the phosphoric acid-based metakaolin geopolymers with HPO/AlO molar ratio of 1.3:1 based on finite element method verified the failure mechanism and the excellent thermal stability at high temperature.
通过调节HPO/AlO比率制备了磷酸基偏高岭土地聚物。采用X射线衍射（XRD）、热重分析和差示扫描量热仪（TG-DSC）、傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）来确定反应过程和相形成。结果表明，由高岭土煅烧得到的偏高岭土主要由石英晶相和非晶相组成。随着HPO/AlO比率的增加，石英的衍射峰明显降低。偏高岭土中过量的石英并未完全参与化学反应。-P-O-Si-O-Al-O的聚合物结构构成了磷酸基偏高岭土地聚物结构的主要组成部分。当HPO/AlO摩尔比为1.3:1时，优化后的抗压强度为29±2MPa。基于有限元方法对HPO/AlO摩尔比为1.3:1的磷酸基偏高岭土地聚物在29MPa载荷下的总变形和1400℃时的总热流进行模拟，验证了其破坏机理和高温下优异的热稳定性。
